World No 1 Aryna Sabalenka's preparations for her US Open title defence have hit a snag after a surprising defeat to Sara Bejlek at the Cincinnati Open. Czech player Bejlek secured the biggest win of her career, beating Sabalenka 7-6(7) 6-4 in the round of 16.
The 20-year-old Bejlek fought back from 5-1 down in a first-set tiebreak and 4-1 behind in the second set to claim her first victory over a top 10 opponent. She will now advance to face Madison Keys in the quarter-finals.
Sabalenka's unexpected exit means that Elena Rybakina has an opportunity to claim the top spot in the world rankings if she reaches the Cincinnati final.
In the men's draw, American Tommy Paul staged a comeback to defeat top seed Alexander Zverev 4-6 7-6(6) 6-4, earning his first spot in the Cincinnati last eight. Paul recovered after a rain delay and saved a match point, eventually winning four straight games in the third set. He is set to play Flavio Cobolli next.